Japanese Yen Deposits - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2025 JPY (¥)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 JPY (¥)	Dec. 31, 2025 JPY (¥)	Dec. 31, 2024 JPY (¥)
Cash and Cash Equivalents [Abstract]
Principal deposits	$ 570,681,631	¥ 82,991,150,290	$ 227,318,113	¥ 33,771,246,366
Principal redemptions	472,654,279	69,548,070,558	104,365,195	16,182,775,633
Withdrawals (to pay expenses)		¥ 352,465,348		¥ 246,065,012
Deposits, interest bearing	$ 475,304,521		$ 390,754,598		¥ 74,501,607,104	¥ 61,410,992,720
Annual nominal rate	0.00%				0.00%